Joanna Boinska

Diurnal variation in platelet inhibition by clopidogrel

Morning increase in the occurrence of myocardial infarction, stroke and sudden cardiac death is a well-recognized phenomenon, which is in line with a morning enhancement of platelet aggregation. We investigated whether platelet inhibition during clopidogrel and aspirin therapy varies during the day. Fifty-nine consecutive patients (45 men and 14 women) with first ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary interventions (pPCI) on dual antiplatelet therapy were prospectively enrolled into the study. Blood samples were collected 4 days after start of clopidogrel treatment at 6.00 a.m., 10.00 a.m., 2.00 p.m. and 7.00 p.m. Arachidonic acid and adenosine diphosphate (ADP)-induced platelet aggregation were assessed by impedance aggregometry. Platelet inhibition by clopidogrel was lowest in the midmorning: median ADP-induced platelet aggregation was 55%, 17% and 27% higher at 10.00 a.m. compared to 6.00 a.m., 2.00 p.m. and 7.00 p.m., respectively (p < 0.002). Nonresponsiveness to clopidogrel defined according to the device manufacturer was 2.4-fold more frequent in the midmorning than in the early morning. We observed a more pronounced midmorning increase in ADP-induced platelet aggregation in diabetic patients when compared to non-diabetics. In contrast, no diurnal variation in the antiplatelet effect of aspirin was observed. In conclusion, in patients presenting with STEMI undergoing pPCI, platelet inhibition by clopidogrel is less strong in the midmorning hours. This periodicity in platelet aggregation in patients on dual antiplatelet therapy should be taken into consideration when assessing platelet function in clinical studies.

Pro-hepcidin and iron metabolism parameters in multi-time blood donors.

A high number of blood donations may cause iron depletion. The pathophysiology behind this process may involve hepcidin, a recently discovered peptide that acts by inhibiting iron absorption and promoting iron retention in reticuloendothelial macrophages. The aim of this study was to determine serum pro‐hepcidin levels and iron metabolism parameters in multi‐time blood donors. The study group consisted of 132 multi‐time male blood donors and 25 healthy male volunteers (nondonors). Complete blood cell count and iron status including serum iron, ferritin, soluble transferrin receptor (sTfR), total iron binding capacity (TIBC), unsaturated iron binding capacity (UIBC), erythropoietin and pro‐hepcidin (ELISA) were assessed. In blood donors, ferritin level drops markedly in relation to donation frequency (P < 0.001). In contrast, TIBC and UIBC levels increase progressively corresponding to annual donation frequency. Pro‐hepcidin concentration increases significantly with the number of donations per year (P = 0.0290). In blood donors having donated blood with the highest frequency per year, pro‐hepcidin levels were positively correlated with haemoglobin (R = 0.31, P < 0.05) and negatively with sTfR (R = −0.31, P < 0.05). Pro‐hepcidin levels increase in relation to blood donation frequency per year. Longitudinal studies focusing on changes in serum hepcidin levels are required to address the question whether hepcidin may contribute to iron metabolism disturbances in multi‐times blood donors.

Which platelet function test best reflects the in vivo plasma concentrations of ticagrelor and its active metabolite

Aim of this study was assessment of the relationship between concentrations of ticagrelor and its active metabolite (AR-C124910XX) and results of selected platelet function tests. In a single-centre, cohort study, patients with myocardial infarction underwent blood sampling following a 180 mg ticagrelor loading dose intake (predose, 1, 2, 3, 4, 6, 12, 24 hours postdose) to perform pharmacokinetic and pharmacodynamic assessments. Platelet reactivity was evaluated using the VASP-assay, the VerifyNow device and the Multiplate analyzer. Analysis of 36 patients revealed high negative correlations between ticagrelor concentrations and platelet reactivity evaluated with all three platelet function tests (the VASP-assay: RS=-0.722; p<0.0001; the VerifyNow device: RS=-0.715; p<0.0001; the Multiplate analyzer: RS=-0.722; p<0.0001), with no significant differences between correlation coefficients. Similar results were found for AR-C124910XX. Platelet reactivity values assessed with all three methods generally correlated well with each other; however, a significantly higher correlation (p<0.02) was demonstrated between the VerifyNow and Multiplate tests (RS=0.707; p<0.0001) than in other assay combinations (the VASP-assay and the VerifyNow device: RS=0.595; p<0.0001; the VASP-assay and the Multiplate analyzer: RS=0.588; p<0.0001). With respect to the recognition of high platelet reactivity, we found higher measurement concordance between the VerifyNow and Multiplate tests compared with other assay combinations, while for low platelet reactivity, only results of the VerifyNow and Multiplate assay were related to each other. Platelet reactivity measurements performed with the VASP, VerifyNow and Multiplate tests show comparably strong negative correlations with ticagrelor and AR-C124910XX concentrations.

CRP, but not TNF-α or IL-6, decreases after weight loss in patients with morbid obesity exposed to intensive weight reduction and balneological treatment.

ObjectiveThe aim of this study was to evaluate the concentrations of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and the degree of homeostasis model assessment-insulin resistance (HOMA-IR) in patients with morbid obesity exposed to a three-week low-calorie diet and balneotherapy.MethodsThe study included 33 patients (25 females and 8 males; mean age 46 years) with body mass index (BMI) values of >40 kg/m2. Evaluations of CRP, IL-6, TNF-α, lipid profile, HOMA-IR, and fasting glucose were carried out before (baseline data) and three weeks after the treatment. The control group consisted of 20 healthy volunteers (15 females and 5 males) with a mean age of 39 years and BMI values of ≤24.9 kg/m2.ResultsIn the blood of patients with morbid obesity we found significantly elevated levels of CRP, TNF-α, triglycerides, HOMA-IR and fasting glucose, but a decreased level of high density lipoprotein (HDL)-cholesterol, compared with the healthy individuals. The treatment resulted in about a 9.4% reduction in body weight from 122.5 to 111.0 kg and a significant decrease in the concentration of CRP, but no change in TNF-α or IL-6. HOMA-IR was significantly reduced.ConclusionThe decrease in CRP level without changes in TNF-α or IL-6 concentrations after the low-calorie diet and balneological treatment, suggests that an essential amount of adipose tissue must be removed before proper adipocyte function is restored. The decrease in HOMA-IR indicates an improvement in insulin sensitivity, which is beneficial in obese patients.概要目的评估病态肥胖患者在低热量饮食和浸浴治疗前后, C 反应蛋白 (CRP)、肿瘤坏死因子α (TNF-α)、白细胞介素-6 ( IL-6) 以及胰岛素抵抗指数 (HOMA-IR) 的水平变化。创新点研究炎症反应对病态肥胖的影响。方法本研究包括33 个病例和20 个正常对照, 对治疗前后的CRP、IL-6、TNF-α、血脂谱、HOMA-IR以及空腹血糖水平进行评估。结论与对照组相比, 低热量饮食和浸浴治疗后, 病态肥胖患者的CRP水平显著降低, 而TNF-α 和IL-6的水平却没有显著变化, 这表明脂肪细胞的正常功能恢复之前必须先去除一定量的脂肪组织。HOMA-IR 水平的降低说明对胰岛素的敏感性有所提高, 这有利于肥胖患者的治疗。

Selected parameters of hemostasis in patients with myeloproliferative neoplasms.

Hemostatic disorders are a major clinical problem in patients with myeloproliferative neoplasms (MPNs) and they are the second most common cause of death in MPN patients, after infections. The aim of this study was to assess the fibrinolytic potential of the blood of patients with MPNs. The study involved 112 patients with MPNs diagnosed at the Hematology Clinic Dr J. Biziel University Hospital No. 2 in Bydgoszcz, Poland. The study group included 63 patients with essential thrombocythemia, 29 with polycythemia vera, 11 with chronic myelogenous leukemia (CML) and nine with primary myelofibrosis. The control group consisted of 25 healthy volunteers who were age and sex-matched. The following parameters were determined: concentration of tissue plasminogen activator antigen (t-PA:Ag), plasminogen activator inhibitor type 1 antigen concentration (PAI-1:Ag), D-dimer, thrombin–antithrombin complexes, fibrinogen, activated partial thromboplastin time and international normalized ratio. The study showed significantly increased t-PA:Ag, PAI-1:Ag and D-dimer levels in patients with MPNs. Moreover, we found increased concentrations of thrombin–antithrombin complexes and fibrinogen, as well as elevated platelet counts. Detailed analysis revealed that t-PA:Ag concentration was elevated in patients with essential thrombocythemia, CML and polycythemia vera. Concentration of PAI-1:Ag was increased in patients with essential thrombocythemia and polycythemia vera; D-dimer was significantly higher in essential thrombocythemia, polycythemia vera, CML and primary myelofibrosis patients. Increased concentrations of t-PA:Ag and D-dimer indicate secondary activation of the fibrinolytic system in patients with MPNs. Elevated levels of PAI-1 in MPN patients may result from its increased production by elevated number of activated platelets and vascular endothelial damage. PAI-1 by having an inhibitory effect on fibrinolysis manifests its procoagulant activity.

ORIGINAL ARTICLE: Pro-hepcidin and iron metabolism parameters in multi-time blood donors

A high number of blood donations may cause iron depletion. The pathophysiology behind this process may involve hepcidin, a recently discovered peptide that acts by inhibiting iron absorption and promoting iron retention in reticuloendothelial macrophages. The aim of this study was to determine serum pro‐hepcidin levels and iron metabolism parameters in multi‐time blood donors. The study group consisted of 132 multi‐time male blood donors and 25 healthy male volunteers (nondonors). Complete blood cell count and iron status including serum iron, ferritin, soluble transferrin receptor (sTfR), total iron binding capacity (TIBC), unsaturated iron binding capacity (UIBC), erythropoietin and pro‐hepcidin (ELISA) were assessed. In blood donors, ferritin level drops markedly in relation to donation frequency (P < 0.001). In contrast, TIBC and UIBC levels increase progressively corresponding to annual donation frequency. Pro‐hepcidin concentration increases significantly with the number of donations per year (P = 0.0290). In blood donors having donated blood with the highest frequency per year, pro‐hepcidin levels were positively correlated with haemoglobin (R = 0.31, P < 0.05) and negatively with sTfR (R = −0.31, P < 0.05). Pro‐hepcidin levels increase in relation to blood donation frequency per year. Longitudinal studies focusing on changes in serum hepcidin levels are required to address the question whether hepcidin may contribute to iron metabolism disturbances in multi‐times blood donors.

VEGF-A and PDGF-BB--angiogenic factors and the stage of diabetic foot syndrome advancement.

INTRODUCTION In patients with diabetic foot syndrome (DFS), an inadequate angiogenic response is observed. The aim of this study was to evaluate the concentrations of VEGF-A, PDGF-BB, sVEGF-R2 and sVEGF-R1 in patients with diabetes-complicated diabetic foot syndrome and analyse them using selected clinical data. MATERIAL AND METHODS Forty seven diabetic patients, 25 women mean age 63 and 20 men mean age 60.5, with diabetic foot syndrome (DFS) were enrolled in the experimental group. To evaluate angiogenesis factors depending on Wagner grade, the subjects were divided into three subgroups: I - patients with 0 Wagner grade (n = 14); II - patients with 1,2,3 Wagner grades (n = 15); and III - patients with 4,5 Wagner grades (n = 18). The control group consisted of 20 healthy volunteers. The material for research was blood. RESULTS Significantly higher levels of VEGF-A and PDGF-BB in the DFS cases compared to controls were observed (VEGF-A p = 0.000001; PDGF-BB p = 0.000051). Analysis of angiogenic parameters according to the stage of diabetic foot syndrome advancement showed higher VEGF-A level (I: p = 0.000867; II: p = 0.001827; III: p = 0.000024) and PDGF-BB (respectively p = 0.004113, p = 0.004224, p = 0.002480) in all the subgroups. Decreased sVEGF-R2 concentrations were observed in the I (p = 0.054) subgroup and the III (p = 0.03524) subgroup. In this study, a strong positive correlation between VEGF-A and PDGF-BB was observed (R = 0.66; p = 0.000001). CONCLUSIONS Our study revealed that proangiogenic factor levels were increased in DFS. This is associated with lower limb ischaemia and hypoxic conditions. The stage of diabetic foot syndrome advancement influenced VEGF-A and PDGF-BB concentrations.

Activation of the tissue factor-dependent extrinsic pathway and its relation to JAK2 V617F mutation status in patients with essential thrombocythemia.

Thrombotic complications may occur in 7.6–29.4% of patients with essential thrombocythemia. According to the cellular theory, tissue factor (TF) activating extrinsic blood coagulation pathway is essential for the activation of blood clotting. The aim of the study was to evaluate the activation of the TF-dependent extrinsic pathway in patients with essential thrombocythemia, depending on the presence or absence of the Janus kinase 2 (JAK2) V617F mutation. The study included 74 newly diagnosed patients (F/M: 47/27; mean age 61 years) with essential thrombocythemia (Tefferi and Vardiman, Leukemia 2008; 22(1):14–22). Patients were diagnosed in the Department of Clinical Hematology and Hematological Malignancies University Hospital No. 2, Bydgoszcz, Poland. The control group consisted of 30 healthy volunteers (F/M: 17/13; mean age 49 years). The concentration and activity of TF and TF pathway inhibitor (TFPI) were measured using ELISA method. In patients with essential thrombocythemia, we observed a higher concentration of TF [median (Me) = 686.90 vs 164.28 pg/ml] and over 10-fold higher activity of TF (Me = 46.05 vs 4.01 pmol/l) when compared with the control group. We also reported significantly higher activity of TFPI compared with the control group (Me = 1.93 vs 1.78 U/ml). Moreover, a concentration of TFPI was significantly lower in patients with essential thrombocythemia with JAK2 V617F mutation as compared with patients without the mutation (Me = 1.90 vs 2.16 U/ml; P = 0.039639). Increased TF activity and concentration is responsible for higher procoagulant potential in patients with essential thrombocythemia. Reduced activity of TFPI in patients with essential thrombocythemia with JAK2 V617F mutation indicates an increased prothrombotic risk in this group of patients.

Angiogenesis in Hodgkin’s lymphoma

Angiogenesis is a multistep process controlled by a number of stimulating and inhibiting factors. Aberrant angiogenesis is involved in cancer progression. The best-known elements responsible for regulation of angiogenesis are vascular endothelial growth factor, their membrane-bound receptors, and circulating, soluble receptors. The major objective of the present review is twofold: firstly, it seeks to explore knowledge about angiogenesis in Hodgkin’s lymphoma, and secondly it indicates the necessity and relevance of carrying out further research dedicated to this process. Hodgkin’s lymphoma is a proliferative disease of the lymphatic system. The process of angiogenesis in Hodgkin’s lymphoma has not been studied thoroughly. There is a significant role of paracrine interactions of Hodgkin and Reed-Sternberg cells with reactive cells of the immune system, which makes studying the mechanisms of development of Hodgkin’s lymphoma more difficult. It has been proven that several angiogenesis-stimulating proteins are expressed in Hodgkin and Reed-Sternberg cells both in vitro and in tumour tissue. Moreover, some of these proteins are produced by the reactive cells. Vascular endothelial growth factor, basic fibroblast growth factor, and hepatic growth factor serum concentrations are elevated in patients with Hodgkin’s lymphoma. The role of circulating endothelial progenitor cells in the pathogenesis of Hodgkin’s lymphoma has not been thoroughly explained. Similarly, there are no satisfying data on the modulation of the angiogenic potential of the blood caused by vascular endothelial growth factor soluble receptors in patients with Hodgkin’s lymphoma. Processes controlling angiogenesis in Hodgkin’s lymphoma merit more comprehensive investigation.

Selected Parameters of Angiogenesis and the JAK2, CALR, and MPL Mutations in Patients With Essential Thrombocythemia:

The aim of the study was to evaluate selected angiogenic factors in patients with essential thrombocythemia (ET) depending on JAK2V617F, calreticulin gene (CALR) and myeloproliferative leukemia virus oncogene (MPL) mutations. Sixty ET patients and 20 healthy volunteers were enrolled in the study. The following tests were performed: vascular endothelial growth factor- A (VEGF-A), soluble vascular endothelial growth factor receptor-1 (sVEGFR-1),soluble vascular endothelial growth factor receptor-2 (sVEGFR-2), platelet-derived growth factor( PDGF-BB), and stromal-derived factor-1α (SDF-1α). We observed an increased PDGF-BB level in patients with ET compared to the controls. Patients with CALR mutation had significantly higher concentration of PDGF-BB and lower concentration of SDF-1α than patients with JAK2V617F mutation. High concentration of PDGF-BB and low concentration of SDF-1α in patients with CALR(+) ET may indicate a contribution of these chemokines in disturbed Ca2+ metabolism in platelets.